Lubricating system and product



Reisaued Jan. 22, 1935 LUBRICATING SYSTEM AND PRODUCT William V. Kidder,deceased, late of La Crosse,

Wis., by Dean Ladd Kidder, execntrix, La

Crosse, Wis.

No Drawing. Original No. 1,877,668, dated september 13, 1932, Serial No.569,354, October 16, 1931. Application for reissue August 20, 1934,

Serial No. 740,717

14 Claims.

This invention relates to lubricating systems and products, particularlyfor the lubrication of the cylinder and piston bearing surfaces ofinternal combustion motors.

The general object of this invention is to improve the recognizedbenefits of lubrication by graphited oils of internal combustion motors,so as to provide a more economical system and. product than heretoforeand to avoid certain difficulties heretofore encountered in the use ofsuch oils.

It is a further object of the invention to minimize the friction betweenthe piston and the cylinder walls due to the occurrence of broken filmsof lubricating oils thereon, and occasioned also by the carbonization ofthe said oils under many conditions of operation, particularly of motorsof automotive vehicles.

It is also an object of the invention to create and maintain a bettercompression in the combustion chambers of motors, by insuring a betterclosure thereof by the piston rings.

Also, an object of this invention is to prevent 'accretions of depositedcarbonaceous materials on the piston head and rings, the upper cylinderwalls, and the valves of motors, which deposits result from the chemicaldecomposition of the oil molecules due to the high temperatures of .theexplosion and of the exhaust gases to which these portions of the motorsare exposed.

Colloidal graphite dispersions in lubricating oils have been used ratherextensively to decreasethe friction and wear of bearing surfaces, duringthe [past quarter of a century or more since such material and its usewas invented and introduced by Dr."Edward G. Acheson. During all of thislong lubricating practice, such use of colloidal graphite hascomprehended its introduction into the bearings of internal combustionmotors exclusively and solely,througl1 the medium of the lubricant inthe-crank case, and never by the admixture of the colloidal materialwith the fuel.

It has been found, however, that the various above-recited objects ofthe invention are attained by adding the colloidal graphite to the fuelitself, such as the gasoline in the storage or supply tank of the motor,and by thereby introducing this microscopically fine and very eflicientheat-resisting solid lubricant into the combustion chamber directly,rather than through the intermediary of the crank case 011. It has beenshown that by this novel means an efficient, high temperature resistinglubrication of the hot cylinder and piston walls is more economicallyaccomplished than heretofore.

The piston head and rings and the cylinder walls are exposed toexploding gases of very high temperatures; and the surfaces" of thesemetal members of the motor consequently acquire temperatures high enoughto occasion a decided lowering of the viscosity of the oil, and,furthermore, the chemical decomposition of the oil molemiles to a minordegree. The result of these combined effects is that the film of oil onthe bearing surfaces of the piston and cylinder becomes so thin, orlight bodied, that the film is occasionally ruptured, particularly bythe shocks of a moving vehicle, and a so-called broken film occurs whichallows occasional contact of metal to metal with consequent increase infriction and heat. a

It appeared that these, and other conditions which it is hardlynecessary to recite, make the problem of lubricating the cylinders andpistons of explosion motors one which is distinct from the lubricationof the crank shaft and connecting rod bearings, etc. in the lower partof the engine by the oil in the crank case. All of these latter bearingsurfaces operate at much lower temperatures than the surfacetemperatures of the piston and cylinder and rarelymuch exceed the,

temperature of boiling water.

. An oil of a body or viscosity suitable for the shaft and connectingrod bearings under all variations of temperature and other conditionsobtaining in the crank case, is therefore too thin for the optimumlubrication of the much hotter cylinder and piston surfaces. Heretoforethe best compromise attainable has been made between the divergentrequirements of these contrasted lubrications. That the compromiseeffected has not been an ideal solution of theproblem is evidenced bythe fact that 50% of the friction in internal combustion motors is thatbetween the piston andcylinders alone.

Dr. Acheson sought to overcome these difficulties about twenty-fiveyears ago by adding colloidal graphite as a stand-by lubricant to crankcase oil, with the thought that the graphoid surface, eventually forgmedthereby on the metal bearing surfaces, would prevent metal-to-metalcontact and the consequent high friction whenever the film of oil itselfwas momentarily broken. The considerable measure of success whichresulted from Achesons system was, however. attained at considerablecost and inconvenience to the automobile owner or dri er. 1

- In eight quarts of crank case 011, for example, weighing, roughly, onthe average, fifteen pounds or about two hundred and fifty, ounces, itwas Moreover, in many instances, acids are developed in the .crank caseoil through oxidation which, it is claimed, flocculate or precipitatethe colloidal graphite when it is present in crank case oil inconcentrations as high as have been employed in the Acheson system. Thisalso impairs the efliciency of the graphite as a lubricant, and, in someinstances, causes stoppage of fine oil ducts or passages by theconsiderable percentage of precipitated graphite:

In U. S. Letters Patent No. 1,879,874, there has been disclosed howavoidance of such precipitation and stoppages may be attained at a muchdiminished cost, without dispensing with the many advantages attendingthe use of colloidal graphite as a constituent of crank case oil. Assaid patent discloses, this is accomplished by reducing theconcentration of the graphite in crankcase oil to between one-half toone-twentieth of that heretofore used. But such diminishedconcentrations, although they are effective as a stand-by lubricant forcrank shaft and connecting rod bearings, are too low for the morestringent requirements of piston and cylinder lubrication at highertemperatures as hereinabove explained.

By the present invention there has been devised a novel colloidalgraphite lubricating system and product, whereby the lubrication of thecylinder and piston walls is effected from a different source oflubricant supply and with dispersions of different orders ofconcentration than has been found to be desirable for the best resultsin the crank case oil. To this end there has been prepared a colloidalgraphite dispersion or suspension in any petroleum or similar organiccompound, but preferably in neutral, filtered lubricating oil, and whichcan be of any suitable concentration, but preferably about 0.2%. This isadded to the gasolene fuel in the tank of the car, for example, in theproportion of four ounces of the dispersion to each five gallons ofgasolene during the first five hundred to one-thousand miles traveledduring its.use. This quantity is sufiicient to establish the desirablegraphoid film under these condltions.

Thereafter, at all times, and to maintain that film against wear, thereis added, for example, one ounce of the 0.2% dispersion to each fivegallons of gasolene used. In an automobile of average efficiency, whichwill travel, say, fifteen miles with each gallon, 66.6 gallons ofgasolene will be consumed for each one thousand miles; and 66.6 dividedby 5, or 13.5 ounces of 0.2% colloidal graphite dispersion in oil, whichwill contain .027 ounce of the solid graphite, will therefore berequired for maintaining a graphoid film in the cylinders and on thepistons by this system. The original conditioning of the motor to buildup such' a film will require four times as much, or about .10 ounce ofsolid graphite, as will be evident" from the foregoing, after which only.027 ounce of the graphite will be requisite for each 1000 car miles.

Five gallons of gasolene will weigh approximately twenty-nine pounds or464 ounces, and in this may be suspended, as above explained, one ounceof 0.2% dispersion, or .002 ounce of the solid colloidal graphite. Theconcentration of the solid graphite suspension in thefuel thereforeneeds to be only about .0004 per cent. Many tests show that this lowconcentration is suificient and attest the remarkable efficiency of thisnovel lubrieating system.

By this improved system, therefore, efiicient cylinder lubrication willbe maintained by the use of approximately one twenty-fifth of the quantity of colloidal-graphite, viz: .75 ounce, required by the Achesonsystem as before explained, with a corresponding reduction in expense.Nevertheless, the suspension of colloidal graphite which 1 is depositedon the hot cylinders and piston walls issubstantially the sameconcentration as was specified by Acheson and those many otherauthorities who helped introduce his systemto automobilists; for all ofthese authorities prescribed from .10.to 30%, or an average of 20%dispersion of graphite, and therefore the same concentration may be usedfor lubrication by the novel means of this system.

Colloidal graphite particles dispersed in oils or other liquids are, asis well known, of microscopic or submicroscopic dimensions; consequentlythey'are readily carried into the combustion chamber of the motor by thestream of air and combustible vapors from the carburetor. Upon enteringthe chamber, much or most of the molecularly fine graphite particlesdeposit, during the compression stroke, on the oily metal surfaces.

Those particles which remain in the explosive 5 mixture in the chamberare projected against and adhere to the oily surfaces by the turbulenceof the explosion.

When used in motors providedwith reasonably clean cylinders, pistonheads and rings and valves, agraphoid film thereon is gradually, builtup by this system during the first one thousand miles or less of use, aswas hereinbefore explained. After the graphoid filmlias begun to buildup, hard, carbonaceous accretions from the burning of lubricating oilwill no longer deposit on the film, to which, for some unknown reason,they do not adhere as they do to bare metal.

. It is well known and established that colloidal graphite fills up thepores and surface inequalities of bearings, and thus insures a morecomplete closure between cylinder walls and piston rings, and, thereby,creates a better compression. This is further promoted by the fact thatthe piston rings, after they are covered by the graphoid film, move morefreely at all times and do not stick to the piston through thedeposition of hard carbonaceous materials.

By the term suspension, as used in the description and claims of thisapplication, there is implied both true dispersions of colloidalgraphite and also physical or chemical states of aggregation such asthose which result from the addition of colloidal graphite dispersionsin oil to other fluids, such as gasolene or its vapors, and which mayalter the physical state of the graphite. It is not definitely knownwhat happens when colloidal graphite dispersions are so suspended,except that the graphite is rendered somewhat less filterable. The termssuspension and suspending, etc., have been used herein to cover suchstates of aggregation in liquids, vapors, and gases, as well as truedispersions. These terms, however, are used to distinguish fromordinary, finely powdered graphite such as was suggested as an additionto lubricating oils by Lucas in United States Patent 721,057, and whichkinds of graphite maybe floated in oils or other petroleum products onlyby mechanical stirring of such liquids.

Although this invention has been described as applied particularly tothe lubrication of the cylinders and pistons on automobile motors, itwill be understood that the system or product is not restricted thereto,but can be used with other internal'combustion motors without departingfrom the spirit and scope of the invention. Many other forms in whichthis invention may be embodied will occur to those skilled in the art,and the fact that there have been specifically illustrated and describedonly a few of such forms is not intended as a limitation.

I claim as his invention:

1. A method of lubricating internal combustion motors, which comprisespreparing a dispersion of colloidal graphite in oil, adding thedispersion to the motor fuel, and introducing the mixture through thecarburetor into the combustion chamber during the operation of themotor.

2. A method of lubricating internal combustion motors, which comprisespreparing a suspension of colloidal graphite in the motor fuel in suchquantity as to give a concentration of approximately .0004% of graphitetherein, and then introducing the mixture through the carburetor intothe combustion chamber during the operation of the motor.

3. A method of lubricating internal combustion motors, which comprisespreparing a dispersion of colloidal graphite in oil, adding thedispersion to the motor fuel in such quantity as to provide aconcentration of approximately .0004% of the graphite therein, andintroducing 'themixture through the carburetor into the combustionchamber during the operation of the motor.

4. A combined fuel and lubricant for internal combustion motors,comprising gasolene and lubricating oil, and a suspension of colloidalgraphite therein.

5. A combined fuel and lubricant for internal combustion motors,comprising gasolene and a suspension of approximately .0004% ofcolloidal graphite therein.

6. A method of lubricating internal combustion motors, which comprisespreparing a suspension of colloidal graphite in the motor fuel in suchquantity as to give a concentration of not more than approximately .0016per cent of graphite therein, and then introducing the mixture throughthe carburetor into the combustion chamber during the operation of themotor.

7. A method of lubricating internal combustion motors, which comprisespreparing a suspension of colloidal graphite in the motor fuel in suchquantity as to give a concentration of from approximately .0004 per centto approximately .0016 per cent of graphite therein, and thenintroducing the mixture through the carburetor into the combustionchamber during the operation of the motor. 1

8. A method of lubricating internal combustion motors which comprisespreparing a suspension of colloidal graphite in a mixture of gasolineand lubricating oil in such quantity as to give a concentration of notmore than approximately .0016

per cent of graphite therein, and then introduc-- ing the mixturethrough the carburetor into the combustion chamber during the operationof the motor.

9. A method of lubricating internal combustion motors havingcarburetors, which comprises preparing a suspension of colloidal.graphite in a mixture of gasoline and lubricating oil in such quantityas to give a concentration sufllciently low to prevent clogging of thecarburetor while being suificient to form a graphoid film in said motor,and then introducing the mixture through the carburetor into thecombustion chamber during the operation of the motor.

10. A combined fuel and lubricant for internal combustion motorscomprising gasoline and a suspension of not more than approximately.0016 per cent of colloidal graphite therein.

11. A combined fueland lubricant for internal combustion motorscomprising gasoline and a suspension of approximately .0004per cent toapproximately .0016 per cent of colloidal graph ite therein.

12. A combined fuel and lubricant for internal combustion motorscomprising gasoline and lubricating oil and a. suspension of not morethan approximately .0016 per cent of colloidal graphite therein.

13. A combined fuel and lubricant for internal combustion motorscomprising gasoline and a suspension of not more than approximately.0016 per cent of graphite which will remain substantially uniformlydistributed throughout said gasoline without mechanical stirring.

14. A method of lubricating internal c'ombus tion motors havingcarburetors, which comprises preparing a suspension of colloidalgraphite in a mixture of gasoline and a petroleum organic compound insuch quantity as to give a concentration sufiiciently low to preventclogging of the carburetor while being sufl'icient to form a graphoidfilm in said motor, and then introducing the mixture through thecombustion chamber during the operation of the motor.

DEAN Erecutrix of the Estate Deceased.

LADD KIDDER, of William V. Kidder,

carburetor into the

